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p iUNlTE'D States PAT NT f Gr mes.

RlCllARD llAUCll, OF l llllll ll'tlil llll), GERMANY, AbfiltlNOlt TO 'llll l FARlilll V FABRIKEN, VOlilliAllS FR. BAYER d: CO, 01! SAME PLACE.

, OLIVE DYE.

$PECIFICA'I'ION forming part of Letters Patent No. 479,515, dated July 26, 1892.

App ication filed November l3 1891. Serial No. 412,312. (Specimens) Patented in France December 2, 1887,110. 137,365.

To all whom, it may concern/.-

Be it known that I, RICHARD LAUGH. "hemist, doctor of philosophy, (assignor to the FAR- BENFABRIKEN, voRnALs FR. BAYER & 00., at Elberfeld,) a subject of the German Emperor, and a resident of Elberfeld, Germany, have invented a new and useful Improvement in the Manufacture of Dye-Stuffs, of which I give in the following a clear and exact description, and for which the aforesaid FAR- BENFABRIKEN have already obtained Letters Patent in France, No. 187,365, dated December :3, 1887.

My invention relates to the manufacture of a new coloring-matter suitable for dyeing unmordantcd cotton by treating with. fuming sulphuric acid the dye-stuff which isobtained by reacting with ne. molecul of tetraze-diphenyl upon one molecule of salicylic acid and one molecule of alpha-nap]ithylamine and by subsequently diazotizing the thus-ob-.

tained product and by combining the formed diazo compound with one molecular proportion of the sodium salt of the dihydroxynaphthaline monosulpho acid described in the Letters Patent No l t 1,679, dated January 13, 1891.

In carrying out my invention practically I proceed as tollowsi 28.9 kilos, by weight, of benzidine sulphate are finely suspended in water, mixed with 56. 1: kilos of hydrochloric acid at 21." llaum and diazotized by a watery solution of fourteen kilos of sodium nitrite. The thus-obtained solution of tetrazo-diphenyl is thereupon added to an icy-cold solution of fourteen kilos of salicylic acid that has been rendered alkaline by the addition of sodium carbonate. hours the production of the intermediate substance is linishcd and a hydrochloricocid solution of 14.3 kilos,by weight, of alpha-naphthylamine is added to thelattcr-n'iixture. After some hours the formation of the azo compound containing molecular proportions of benzidine,salicylicacid,andalplra-naphthylamine is finished by heating for a short time at about St)" centigradc. .lly filtering the dark precipitate, by washing with water, and drying the intermediate dye-stuff is isolated. i-ilty kilos oi this dried product are introd uced 'im sum-ll portions li i to two hundred After standing for some kilos of fuming sulphuric acid containing about twenty per cent. of anhydride, taking care that the temperature does not rise above 20" centigrade. When a test sample perfectly dissolves in sodium carbonate, the pro ccss of'sulphonation is finished. The mixture then is poured on ice and the precipitate, thereby separating, is filtered oil and washed with cold water. The thusbtained new sulpho-acid is dissolved in alkali and mixed with a watery solution oi? seven kilos, by weight, ol sodium nitrite. The mixture, after having been czn'cfully cooled by ice, is acidulated on stirring by slowly adding muriatieaeid. Theprecipitate,atiirstbrown-black, gradually becomes clearer, and when after about twelve hours the diazotation is finished the brown-red precipitate is added to an alhaline solution of twenty-seven kilos, by weight, of the sodium salt of the dihydroxyuaphtha;

'liue mouosulpho-acid described in the Letters Patent No. +t4-i,(i7.), dated January til, 1801, taking care by the addition of sodium earbonate that the liquid remains alkaline during the whole process. After some hours the mixture is heated to about 80" centigrade, whereby the coloring-matter is'separatcd almost perfectly, and the quantity which remains in solution is salted out.

After having been filtered oil and dried my new coloring-matter forms a brownishblaek powder which is moderately soluble in cold, more easily in hot, water with olive color. It dissolves in sodiu m carbonate, with deep green, which is changed by an excess olf the latter reagent into a brownish rod. ()n addition of soda-lye or ammonia to thewatery solution of the eoloring matter a lnownish-red liquid results. \Yhen its watery solutions are mixed with acids, at grayislrgreen precipitate is separated, while the supernatant liquid becomes almost colorless. It is soluble in concentrated sulphuric acid, with a violet; color, out of which solution a blackish-green precipitate separates on the addition ot water. It produces on unmordauicd cotton in an all ka-linc-soap bath olive-colored shades.

Having thus described my invention,what I claim as new, and desire to secure by [letters 1atent,is-

l. The processolf producinga new coloring-- powder difiicultly soluble in cold water and more easily in hot water and soluble in diluted solutions of sodium carbonate, with olive color, which latter becomes brownish red by adding sodium carbonate in excess, soluble in soda-lye and ammonia, with brownish-red color, from which on the addition of acids a grayish-green fine precipitate separates, the liquid becoming almost colorless; in concentrated sulphuric acid it dissolves, with violet color, that turns green by adding water, but after some time a blackish-green precipitate separates and the liquid becomes almost col-- orless, and it dyes unmordanted cotton olive in alkaline-soap baths.

In testimony whereof I have signed my name in the presence of two subscribing witnesses.

RICHARD LAUGH.

\Vitnesses:

WM. ESSENWEIN, RUDOLPH FRICKE. 

